Antioxidant xanthones from Cratoxylum cochinchinense

A new xanthone named cratoxylumxanthone A (1), together with five known compounds: dulcisxanthone B (2), alpha-mangostin (3), beta-mangostin (4), 2-geranyl-1,3,7-trihydroxy-4-(3-methylbut-2-enyl)xanthone (5) and tectochrystin (6), was isolated from Cratoxylum cochinchinense stems. The structure of new compound was characterized by 1D and 2D NMR techniques. The isolated compounds showed free radical scavenging against DPPH and lipid peroxidation inhibition.